The trend in very-large-scale integration (VLSI) technology has resulted in narrower interconnection lines and smaller contacts. Furthermore, integrated circuit designs are becoming more complex and denser. More devices are compressed in integrated circuits to improve performance.
In the design of an integrated circuit, standard cells having predetermined functions are used. Layouts of standard cells are stored in cell libraries. When designing an integrated circuit, the respective layouts of the standard cells are retrieved from the cell libraries and placed into one or more desired locations on an integrated circuit layout. Routing is then performed to connect the standard cells with each other using interconnection tracks.